The present invention relates to spatial compounding. In particular, the present invention relates to compounding component frames of data associated with different angles to reduce speckle and produce a more continuous border in specular targets, such as muscle layers.
One component frame of data is acquired by scanning along scan lines at one angle or pattern relative to a transducer. A second component frame of data is acquired by scanning along scan lines at a different angle or pattern. Each of the frames of data represents a different but overlapping region of a patient due to the angle or pattern of the scan lines. The frames of data are compounded together and displayed as an image. The transducer is held at substantially one position on the patient for acquiring the sequential component frames of data.
Steered spatial compounding may mask or change the appearance of clinical markers. Clinical markers are an important diagnostic tool. Either shadows (i.e. dark lines) or a brightened area (i.e. bright lines) are produced in the images of surrounding tissue by objects or obstructions in the body. Calcifications produce shadows. Fluid filled cysts often produce brightened areas. The markers are frequently used to help identify pathology. The appearance and orientation of these markers depends on the orientation of the ultrasound beams. As a result, compounding frames of data associated with different steering angles or patterns reduces or eliminates desirable markers in the resulting compound image.
In one system, a non-spatial compounded image is displayed in a dual type display mode. The non-spatial compound image is frozen on the display. A live or real time spatial compounded image is then displayed next to the frozen image on system. However, the frozen image provides little continuingly useful information as the transducer or patient move.